Question

If AB = 10 cm & DB = 40 cm (diameter). What is the radius of curvature and the focal length of the spherical glass respectively?
40 cm, 10 cm
20 cm, 20 cm
40 cm, 5 cm20 cm, 10 cm​

Answer 1

40 cm, 5 cm20 cm, 10 cm

correct answer

Answer 2

Explanation:

we have given that,

diameter is 20 cm

therefore, radius = diameter/2

= 40/2

= 20 cm

therefore radius of curvature is 20 cm

we know that,

focal length of spherical glass is equal to radius of curvature

therefore focal length of spherical glass is 20 cm

answer :

20 cm , 20 cm